Supplements (or really anything I put in my mouth) is one of a growing set of classes of items I won't buy on Amazon anymore. That probably doesn't result in much loss for Amazon right now, but what it does do is:
1. Makes me trust Amazon MUCH less, which means I'm much more likely to forgo purchasing additional classes of items from them.
2. Makes me find new online or offline vendors for the classes of items I no longer buy from Amazon. Those vendors sometimes sell other items I would normally buy from Amazon as well. If I need those items, I'm not going to shop BOTH places. I'm going with the one I trust.
3. Makes me reconsider my Prime membership. (Among other things, like shipping having become less reliable recently.)
There's a tipping point here somewhere, where I'll just stop being an Amazon customer entirely.